Combined hot water steel liquid or gaseous fuel boiler EST-EKO, Powers 20-3500kW, could be used for all heating systems in both individual and commercial and industrial buildings. Operating regime is 90/70 [° C] at a working pressure of up to 2.5 [bar]. The boiler is made of high quality boiler plate, in accordance with EN303-1, EN303-2, EN303-4 and ISO9001-2008. Fuel combustion is performed in cylinrical reversible flame tube. Flue gases, which are made as products of combustion, returning from the flame tube and the tube bundle, and go into the atmosphere through the flue and chimney. The boiler door is designed to allow easy installation of the fan burners that are currently on the market. Combustion in boilers with liquid or gaseous fuel is regulated by automatic for proper burner, which is installed on the boiler and connected to the burner. The construction of these boilers is such, that in operation provides maximum utilization of heat energy, reliable operation and a long service life. The boiler contains all the necessary ports for connecting to the installation (connection to the water supply to the boiler, access to drain water from the boiler connection for safety valve, plug valve.), EKO Boiler body is corrosion protected by a special coating, thermal insulation mineral wool, which is located in the hull of the plastic sheet. We manufacture boilers with liquid or gaseous fuel, high power from 2000 to 3500kW with a different structure for these data are given on request.